Wednesday, May 5, 2010

How Do Sea Mammals Breathe?

Whales, dolphins and manatees have very efficient lungs. Even though the lung volume is less than terrestrial animals, they can exchange up to 85-90% of the air, whereas a human exchanges only 15% of the air. This efficiency in breathing allows aquatic mammals to be submerged for several minutes to almost an hour. Air is breathed through blowhole, situated almost directly on top of the head. The dolphin normally comes to the surface to breathe about every two minutes,and each breath consists of a short, almost explosive exhalation, followed by a slightly longer inhalation.